page 2 – 50
2001 / Jul 01
H A R D W A R E
Stacking Card (CEX-2001)
Overview
The Stacking card is used to connect up to 4 co-located racks into a larger
virtual chassis. The stacking approach is most useful when configuring
medium to large centrally located systems which employ a large number of
analog or digital audio I/O cards. Stacked racks allow full physical access to
all 32 TDM busses by expanding the number of available slots. Remember,
a single chassis has 22 slots which can accommodate a maximum of 20 I/O
cards, whereas a four rack stacked system for example has 88 slots. Only one
chassis (the master chassis) may have an active CPU card.
Configuring the Virtual Chassis
Each stacked chassis must have a single
CEX-2001 chassis expansion card installed in
Slot 1. Each CEX-2001 card is chained together
using the provided high density multipin cables,
similar to that used in SCSI interfaces (pinouts are
NOT identical to SCSI). A cable from Rack1 con-
nects to Rack 2, Rack 2 to Rack 3, etc. The supplied
termination plugs must be fitted to the unused
connectors at both ends of the chain.
TDM Assignment
When configuring stacked systems, attention
must be given to the number of TDM busses allo-
cated to the master chassis and each expansion rack.
The number of TDM busses in a rack determines the
number of input cards allowed in a rack. Each input
card uses one TDM bus.
The 4 position dipswitch SW3 allows the user to allocate TDM busses in
groups of 8, with each switch position allocating 8 TDM busses. The first
position of SW3 on the CEX-2001 in the master chassis must always be ON,
and conversely the first position of SW3 on the remaining CEX-2001 cards
installed in the expansion racks must always be OFF. How you set the
remaining 3 positions of dipswitch SW3 on each CEX-2001 card determines
how many TDM busses are available to each rack. For example, assume a 2
rack system: switch ON SW3, positions 1 & 2 on the master rack CEX-2001
and SW3, positions 3 & 4 on the second rack’s CEX-2001 card. The master
rack and the expansion rack now each drive 16 TDM’s, giving each rack the
ability to house up to 16 input cards each.
MASTER
STACK
RACK IDØ
CAGE 1
RACK ID1
CAGE n
RACK IDn
TERMINATOR
CABLE
CABLE
TERMINATOR